Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02257796 1998-12-07
WO 97/48736 _ 1 _ PCT/US97/10418
SUPPORTED LATE TRANSITION METAL CATALYST SYSTEMS
FIELD OF THE INVENTION
This invention relates to supported late transition metal catalyst systems,
means of
preparing them and polymerization of olefins using them.
BACKGROUND OF THE INVENTION
Early transition metal catalysts for olefin polymers by coordination
polymerization
are well-known, typically those are the traditional Ziegler-type catalysts
based on Group 4
and 5 of the Periodic Table (ILTPAC new nomenclature) and the newer
metallocene catalysts
based on Group 4 - 6 metals. However specific late transition metal catalysts
suitable for
olefin polymerization had not offered the same levels of activity or molecular
weight
capability for olefin polymerization during the development of these catalyst
systems and
additional work was published addressing this lack.
In Johnson, Killian, and Brookhart, J. Am. Chem. Soc., 1995, 117, 6414 the
authors
describe the use of Ni and Pd complexes for the solution homopolymerization of
ethylene,
propylene, and 1-hexene. The catalyst precursors are square-planar, M2+, d8,
16 electron
complexes incorporating substituted, bidentate diimine ligands. The active
coordination sites
are occupied by either methyl or bromide ligands. Methyl ligand complexes were
activated
with H+(OEt2)2[B(3,5-(CF3)ZC6H3)4]- and bromide ligand complexes were
activated with
methylalumoxane (MAO) or diethylaluminumchloride as cocatalysts.
European patent publication EP-A2-0 454 231 describes Group VIIIb metal
catalysts
said to be suitable for the polymerization of ethylene, a-olefins, diolefins,
fixnctionalized
olefins, and alkynes. The described catalyst precursors are Group VIIIb metal
(Groups 8, 9,
10, IUPAC new nomenclature) compounds which are subsequently activated by
compounds
including discrete borate anions. Ethylene homopolymerization in solutions of
methylene
chloride, toluene and diethyl ether are illustrated. Few polymerizations were
conducted in
the presence of a support material and broad molecular weight distribution
polymers were
produced.
The advantages recognized with the early transition metal catalysts of
immobilizing
the catalyst on solid supports to enable heterogeneous polymerization
processes such as
those based on gas phase, bulk or slurry processes would be important to
effect efficient
industrial utilization of the late transition metal catalysts described, and
derivatives of them.
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In particular, due to the observed high levels of bratlchung with the
catalysts of the above
literature, melting points of the resulting polymers were anticipated to be so
low as to
present problems with reactor operation at typical industrial operating
temperatures
occurring when heat dissipation by solvents is unavailable, as irl continuous
gars phase
polymerization_
SUMMARY OF TF~ INYENT'ION
The invention encompasses late transition metal catalyst systems immobilized
on solid
supports and their use in heterogenous polymerization processes, particularly
in gas phase
polymerization of ole5n monomers. Preferred embodiments include a late
transition metal
catalyst system comprising a Group 9, 10, or 11 metal complex stabilized by a
bidemate
ligand structure immobilized on a solid porous metal oxide, metalloid o~dde or
polymeric
particle support, preferably those comprising silica. The gas phase
polymerization process for
olesn monomers comprises contacting one or more olefins arith these catalyst
systems under
gas phase polymerization conditions.
DfiTAILBI~ DESCR~T10N OF TF~ iNVENT:foN
The polymerization catalysts of this invention can be derived from the late
transition
metal compounds of formula:
LMXr
wherein M is a Group 9, 10 or 11 metal with the proviso that M is not
palladium, preferably a first row
metal, also preferably a db, dg or d'° metal, most preferably d8; L is
a bidentate ligand that stabilizes a
square planar geometry and charge balances the oxidation state of MXl; each X
is, independently, a
hydride radical, a hydrocarbyl radical, a substituted hydrocarbyl radical, a
halocarbyl radical,
a substituted halocarbyi radical, and hydrocarbyl- arid halocarbyl-substituted
organometalloid
radicals; or two X's are joined and bound to the metal atom to form a
me2all~cle ring
containing from 2 to 20 carbon atoms; or one or more X can be a neutral
hydrocarbyl
hydrocarbyl containing donor ligand, e.g., an olefin, diolefin, or aeyne
ligand; and r a O, 1, 2,
or 3. When Lcwis-acid activators, such as methylalumoxane, aluminum alkyls, or
allcylaluminursi halides, which are capable of donating an X ligand, as
described above, to the
transition metal component, are used, or when the ionic activator is capable
of extracting 7~
one or more X may additionally be independently selected from the
group consisting of a halogen, alkoxide, aryloxide, amide, or phosphide;
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two such X's joined to form an anionic chelating ligand; or, one or more
neutral non-hydrocarbyl
atom containing donor ligand, e.g., phosphine, amine, nitrite or CO ligand.
Iti a pl~fC~ed embodimcut of the iaYCntioa, hho bideatate ligand, L, is de5ned
by
the allowing formula:
P
A
Rr,~'-E~ 1E-...R~~
wherein R is a bridging g:'oup containing a Gtoup '13-15 clearest; cac~, E is
iadap~adeatly
a Group I S or z fi elemtrzt bos~dod to M; eaols R is iadepeadmtly a C1-C3p
contsming
radical or diradical group which is a lsydrocsrbyl, aubstaruted-hydrocatbyl,
halocarbyl,
aubstit~haloearbyl, hydrocarbyl-aubstitu~ed nrganometelloid, halocacbyl-
substituted
organometalloid, m and n sre indep~delltly 1 yr x depcuding on the walcacy of
E; and p
is the Chatgo ou tho bidcntate ligawd ~cls that the oxidation state of MX= i,s
satie8ed.
In the xonst preferred Embodiment of the iavcntion, the bridging group, A, is
dGfiaed by tb,s following formulae:
'~. _~'~'
~G~ R~ R~ ~G ~ R~ ,G ~
,~ A-t A~Z ' A-3 A~4 A-6
Q
\ ~~ ! \ / \
A.9 A-T A~1 A.4 A-,o
R'
a~
~ R.
R'
R
1
A-11 A.12 A~13 A
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WO 97/48736 _ 4 _ PCT/L1S97/10418
wherein G is a Group 14 element especially C, Si, and Ge; Q is a Group 13
element
especially B and Al; and R' are independently hydride radicals, C1-C30
hydrocarbyl radicals,
substituted hydrocarbyl radicals, halocarbyl radicals, substituted halocarbyl
radicals, and
hydrocarbyl- and halocarbyl-substituted organometalloid radicals, and
optionally two or
more adjacent R' may form one or more C4 to C40 rings to give a saturated or
unsaturated
cyclic or polycyclic ring.
Also in the most preferred embodiment of the invention, each R is
independently a
bulky C1-C30 containing radical group which is a hydrocarbyl, substituted-
hydrocarbyl,
halocarbyl, substituted-halocarbyl, substituted organometalloid, hydrocarbyl-
substituted
organometalloid, or halocarbyl-substituted organometalloid. Bulky radical
groups include
phenyls, substituted phenyls, alkyls and substituted alkyls bonded to E
through a tertiary
carbon atom, alicyclic and polyalicyclic containing hydrocarbyls, particularly
those bonded to
E through a tertiary carbon and the like.
In the definitions above, the term "substituted" is as defined or refers to C1-
C30
containing radicals which are to be essentially hydrocarbyl, but may include
one or more non-
hydrocarbyl atoms (such as Si, Ge, O, S, N, P, halogen, etc.) in place of one
or more carbon
atoms.
In the very most preferred embodiment of this invention, M is a group 10
metal, E is
a group 15 element especially nitrogen with m and n being one and p being
zero, the bridge
is as drawn in A-l, and R is a substituted phenyl group preferably substituted
in at least the 2
and 6 positions with non-hydride R' groups. For high molecular weight
polymers, R' is
preferably C3-C3o, preferably with a secondary or tertiary carbon atom bonded
to the phenyl
group.
For the purposes of this patent specification, the terms "cocatalysts or
activators" are
used interchangeably and are defined to be any compound or component which can
activate
the late transition metal compound.
The late transition metal catalyst compounds according to the invention may be
activated into the invention catalyst complexes for polymerization catalysis
in any manner
sufl'lcient to allow coordination polymerization. This can be achieved, for
example, when
one X ligand can be abstracted and the other X will either allow insertion of
the unsaturated
monomers or will be similarly abstractable for replacement with an X that
allows insertion of
the unsaturated monomer. Traditional organometallic compound Ziegler
cocatalysts may be
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WO 97/48736 _ 5 _ PCT/US97/10418
utilized. Additionally, the traditional activators of metallocene
polymerization art are
suitable activators; those typically include Lewis acids such as alumoxane
compounds, and
ionizing, anion pre-cursor compounds that abstract one X so as to ionize the
transition metal
center into a cation and provide a counterbalancing, compatible,
noncoordinating anion.
In general, the late transition metal compound may be activated with an
alumoxane,
Ziegler cocatalyst, "noncoordinating anion" precursor compounds and halide
salts of the
Group 13-16 metals each of which is described more fully below.
The Ziegler cocatalyst will typically be a organometallic compound of a metal
of
Groups 1, 2, 12 or 13 of the Periodic table of elements. Preferred are
organoaluminum
compounds selected from the group consisting of aluminum alkyl, aluminum alkyl
halide and
aluminum halide. These can be represented by the formulae
AI(R')sX'3_s, wherein R' is independently a hydride or C1 to
C,o hydrocarbyl radicals including aliphatic,
alicyclic or aromatic hydrocarbon radical, X' is
a halogen and s is an integer from 0 to 3; and,
A12R'3X'3 which are hydrocarbylaluminum sesquihalides.
Examples include triethylaluminum, triisobutylaluminum, diethyl aluminum
chloride,
A12Et3C13 and Al2(i-Bu)3C13.
Alkylalumoxanes and modified alkylalumoxanes are suitable as catalyst
activators.
The alumoxane component useful as catalyst activator typically is an
oligomeric aluminum
compound represented by the general formula (RZ-Al-O)n, which is a cyclic
compound, or
RZ(R2-Al-O)nA1R22, which is a linear compound. In the general atumoxane
formula RZ is
independently a C 1 to C 10 hydrocarbyl radical, for example, methyl, ethyl,
propyl, butyl or
pentyl and "n" is an integer from 1 to about 100. Most preferably, R2 is
methyl and "n" is at
least 4. Alumoxanes can be prepared by various procedures known in the art.
For example,
an aluminum alkyl may be treated with water dissolved in an inert organic
solvent, or it may
be contacted with a hydrated salt, such as hydrated copper sulfate suspended
in an inert
organic solvent, to yield an alumoxane. Generally, however prepared, the
reaction of an
aluminum alkyl with a limited amount of water yields a mixture of the linear
and cyclic
species of the alumoxane. Methylalumoxane and modified methylalumoxanes are
preferred.
For further descriptions see, U.S. Patent Nos. 4,665,208, 4,952,540,
5,041,584, 5,091,352,
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to
5,206.199, 5.204,419, 4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,329,032,
5,248,801,
5,235,081, 5,157.137. 5,103,031 and EP 0 561 476 Al, EP 0 279 586 131, EP 0
Slb 476 A,
EP 0 594 218 A1 and WO 94/10180.
For the immobilized catalyst systems of t~,e invention when the activator is
an
alumoxane, the pre~rred transition metal compound to activator molar ratio is
tom, 1:500 to
10:1, more preferably ~ro~on about 1:200 to 10:1, even more preferably ~rom
about 1:120 to
1:1.
?he term "noncoordinating atdon" as used for the ionizing, anion pre-cursor
compounds (°'noncoordinating anion precursors") is recognized to mean
an anion which
either does not coordinate tv said transition metal canon or which is only
weakly coordinated
to said canon thereby remaining sufficiently labile to be displaced by a
neutral Lewis base.
°°Compatible" noncoordinating anions are those which are not
degraded to neutrality when
the initially formed complex between the late-transition-metal catalyst
compounds and the
ionizing, anion pre-cursor compounds decomposes. Further, the anion will not
vansfer an
anionic substituent or fragment to the ration so as to cause it to form a
neutral four
coordinate metal compound and a neutral by-product from the anion.
Noncoordinating
anions useful in accordance with this invention are those which are
compatible, stabilize the
late-transition-metal ration in the sense of balancing its ionic charge, yet
retain sufl5cient
lability to permit displacement by an olefinically unsaturated monomer during
polymerization.
Additionally, the anions useful in this invention will be of suffcient
molecular size to partially
inhibit or help to prevent neutralization of the late-transition-metal ration
by Lewis bases
other thin the polycrlerizable monomers that may be present in the
polymerization process.
l7esctiptiona of ionic catalysts, those comprising a transition metal ration
and a
noncoordinating anion, suitable for coordination polymerization appear in the
early work in
U.S. patents 5,064,802, 5,132,380, 5,198,401, 5,278,119, 5,321,106, 5,347,024,
5,408,017,
WO 92!00333 and WO 93/14132. These teach a preferred method of preparation
wherein
metallocenea are protonated by an anion precursor such that an alkyllhydride
group is
abstracted from a transition metal to make it both cationic and charge-
balanced by the
no~coordir~ating anion. These teachings are useful to those skilled in the art
for the late-
traruition-metal catalysts of the present imrention
The use of ionising ionic compounds not containing an active proton but
capable of
producing both the active metal ration and a noncoordinating action is also
known. See, EP-
A-0 426 637, EP..A-0 573 403 and U.S. patent 5,387,568. Reactive rations other
than the
CA 02257796 2004-09-29
Bronsted acids include ferricenium, silver, tropylium, trAphenylcarbetdunct
and ttiethylsilylium,
or alkalis metal or ailtaline earth metal rations such as sodium, tnagnesiu~m
or lithium rations.
A further class of noncoordinating anion precursors suitable in accordance
with this
invention are hydrated salts comprising the alkali metal or alkaline earth
metal rations and a
noncoordinating anion as described above. The hydrated salts can be prepared
by reaction of
the metal ration-noncoordinating aruion salt with water, for example, by
hydrolysis of the
commercially available or readily synthesized LiB(pfp)4 which yields [Li~xH20]
[B(pfp)a),
where (pfp) is pentafluorophenyl or perfluorophenyl.
1 O Any rneta! or metalloid capable of forming a coordination complex, which
preferably is
resistant to degradation by water (or other Bmnsted or Lewls Acids), may be
used or
contained in the anion. Suitable metals include, but are not limited to,
alununum, gold,
platinum and the like. Suitable metalloids include, but are not limited to,
boron, phosphorus,
silicon and the like.
An additional method of making the ionic catalysts uses noncoordinating anion
precursors which are initially neutral Lewes acids but form the ration and
anion upon ionizing
reaction with the late transition metal compounds, for example
tris(pentafluorophenyl) boron
acts to abstract a hydroearbyt, hydride yr sityl ligand to yield a late-
transition-metal ration
and atab3liiing noncoordinating anion; see EP-A-0 427 697 and EP-A-0 520 732
which are
directed to metallocene catalyst systems. Ionic catalysts for coordination
polymerization can
also be prepared by oxidation of the metal centers of transition metal
compounds by anionic
precursors containing metallic o~ddizing groups along with the anion groups,
see EP-A-0 495
375.
When the ration portion of an ionic nvncoordinatiag precursor is a Bronsted
acid such
as protons or protonated Lewes bases, or a reducible Lewes acid such as
fenicanium or silver
rations, or alkali metal or alkaline earth metal rations such as those of
8odiu~ magnesium or
lithium rations, the transition metal to activator molar ratio may be any
ratio, Gut preferably
from about 10:1 to 1:10; more preferably from about S;1 to 1:5; even more
preferably from
about 2:1 to 1.2; and most preferably from about 1.2:1 to 1:1.2 with the ratio
of about 1:1
bang the most preferred. Similar ratios may be used for other noecoordinating
anion
precusor compounds.
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WO 97/48736 _ g - PCT/US97/10418
The late transition metal catalyst compounds of this invention may also be
activated
with ionizing anion precursors including the halide salts of Group 13 -16
metals or
metalloids, preferably the fluoride and oxyfluoride salts, e.g., those
providing the following
anions: BF4 , PF6 , SbF6 ; TeOF6 and AsFb .
When halide salts of Group 13-16 metals or metalloids are used as the
activator, the
preferred total transition metal compound to activator molar ratio is
preferably from 10:1 to
1:10, more preferably from about 5:1 to 1:5, even more preferably from 2:1 to
1:2, and even
more preferably from 1.2:1 to 1:1.2 with 1:1 being most preferred. Higher and
lower ratios
may also be used.
When using ionic catalysts of the late transition metal complexes comprising
cations
and noncoordinating anions, the total catalyst system can additionally
comprise one or more
scavenging compounds. The term "scavenging compounds" is meant to include
those
compounds effective for removing polar impurities from the reaction
environment.
Impurities can be inadvertently introduced with any of the polymerization
reaction
components, particularly with solvent, monomer and catalyst feed, and
adversely affect
catalyst activity and stability. Impurities can result in decreased, variable
or even elimination
of catalytic activity. The polar impurities, or catalyst poisons include
water, oxygen, metal
impurities, etc. While the late transition metal catalysts of the present
invention can be less
sensitive to impurities than metallocene catalyst systems, reduction or
elimination of poisons
remains a viable option. Preferably steps are taken before provision of such
into the reaction
vessel, for example by chemical treatment or careful separation techniques
after or during the
synthesis or preparation of the various components; some minor amounts of
scavenging
compound can still normally be used in the polymerization process itself.
Typically the scavenging compound will be an organometallic compound such as
the
Group 13 organometallic compounds of U.S. patents 5,153,157, 5,241,025 and WO-
A-
91/09882, WO-A-94/03506, WO-A-93/14132, and that of WO 95/07941. Exemplary
compounds include triethyl aluminum, triethyl borane, triisobutyl aluminum,
methylalumoxane, isobutyl aluminoxane, and n-octyl aluminum. Those scavenging
compounds having bulky or Cg-C20 linear hydrocarbyl substituents covalently
bound to the
metal or metalloid center being preferred to minimize adverse interaction with
the active
catalyst. When alumoxane or Zeigler co-catalyst is used as activator, any
excess over the
amount of late-transition-metal present will act as scavenger compounds and
additional
scavenging compounds may not be necessary. The amount of scavenging agent to
be used
with late-transition-metal cation-noncoordinating anion pairs is minimized
during
polymerization reactions to that amount effective to enhance activity.
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The catalyst systoms of this invention can additionally be prepared by
combining in
any order the bidcntatc Ggand L, or a known precursor to it, with a suitable
late transition
metal complex, and an aetiyatoc compound. For example, the bidentate ligand L
precursor
(2,6-i-PrzC6Fi3N°~CH)z may be added to the late transition metal
complex
NiBr~~MeOCHsCI~IZOMe in a solvent such as toluene having the activator
compound
methylalumoxane dissolved therein. Optionally, oxidizing or reducing agents
may be used
additionally to achieve the preferred d6, dg or dI0 metal eornpounds. All
reactants may be
addod is arty order, or even essentially simultaneously.
The supported catalyst can be prepared in an appropriate solvent which may be
any
of aliphatic or aromatic hydrocarbon solvents, halocarbon solvents such as
mechylene
chloride and difluorobenzene, or may be polar or protie solvems such as water.
The
halocarbon or polar solvents are preferred when the late transition metal
compounds, LMXr.
are not soluble in hydrocarbon solvents. Typically the aromatic hydrocarbon
solvents are
more suitable than the aliphatic solvents for dissolving the late transition
metal compound.
Further, the aromatic hydrocarbon solvents can be used for late transition
metal compounds
having limited solubility in those solvents when the metal compounds have been
solubilized
with a suitable activator, for example, as with actavauon by tnethytalumoxane
in an aromatic
solvent_ Significant dissolution of the metal compounds is important for the
preparation of
homogeneous, supported catalysts. The term "homogeneous, supported catalysts"
means
that the traetal compounds, or their activated cotrtplexes, approach even
distribution upon the
accessible surt~ce area of the support, including interior pore surfaces in
the preferred porous
supports.
ZS
The imtnobiiized catalyst systems of the invention may be prepared by any
effective
method of supporting other coordination catalyst systems, a#fective meaning
that the catalyst
so prepared can be used for preparing polymer in a heterogeneous
polymerization process.
In accordance with one method, as illustrated in the examples below, the late
transition metal
compound is combined with an activator compound in solvent to prepare a
precursor solution
which is added to a porous support particle in such a manner that the total
solvent volume
exceeds the total particle pore volume but is less than that at which the
formation of a slurry is
observed.
Another preferred method of immobilizing the catalyst systems of the invention
is described
in WO 96/04319. In this method ionic catalyst systems chemically bound to the
support are
CA 02257796 2004-09-29
1~
prepared. A neutral Lcwis acid ioniang compound (such as
trisperfluorophenylbvron) is
reacted with hydroxyl group~containing metal oxide supports, preferably
cvmplexed with a
Lewis base, and they reacted with the transition metal precursor compound
which is
activated by protonation. The late transition metal activated complex is then
ivnucaUy
balanced by the noncoordinating anion chemically bound to the support.
The activated catalyst may also be supported in accordance with WO 9110882 and
WO 94/03506. particularly when using ionizing activators providing
electronically stabilizi~
noncoordinating anions. In this method, inorganic oxide particle supports are
treated with a
Lewis acid to neutralize any hydroxyl groups remaining on the surfaces aRer
thorough drying
and prior to the adsorption of the activated catalyst complex from the
solution in which it is
added.
Additional methods appear in the following descriptions for metallocene
catalysts,
these methods will be suitable as well for the invention catalyst systems.
U.S. Patent No.
4,937,217 generally describes a mixture of trimethylaluminum and
triethylaluminum added to
an undehydrated silica to which a metallocene catalyst component is then
added. EP-
308177~B 1 generally describes adding a wet monomer to a reactor coetaining a
mecallocene,
nialrylaluminum and undehydrated sllica_ U-S. Patent Nos. 4,912,075, 4,935,397
and
4,937,301 generally relate to adding trimethylalutnittum to art un~deh~ydrated
silica and then
adding a metallocene to fbrra a dry supported catalyst system. U.S. Patent No.
4,914,253
describes adding triunethylaluminuna to undehydrated silica, adding a
maallocecte and then
drying the resulting supported catalyst system with azt amount of hydrogezt to
produce a
polyethylene vsrax_ U.S. Patent Nos. 3,008,228, 5,086,025 and 3,147,9x9
generally describe
forming a dry supported catalyst system by the addition of trimethylaluminum
to a water
impregnated silica to form alumoxane in situ and then adding the metallocene.
U.S. Patent
Nos. 4,808,561, 4,897,455 and 4,701,432 describe techniques to form a
supported catalyst
where the inert carrier, typically silica, is calcined and contacted with a
mttallocene(s) and an
arctlvator/cocatalyst component. U.S. Patent No. 5,238,892 describes forming a
dry
supported catalyst system by mixing a metallocene with an alkyl aluminum and
then addlnig
undehydrated silica. U.S. Patent No. 5,240,894 generally pertaiuws to
for~m~ing a supported
m~etalloc~e/alumoxane catalyst system by forming a metallocendalutnoxaune
rcacdott
solution, adding a porous carrier, and evaporating the resulting slurry to
remove essentially
alt residual solvent from the carrier.
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WO 97/48736 - 11 _ PCT/US97/10418
Polymeric carriers will also be suitable in accordance with the invention, see
for
example the descriptions in WO 95/15815 and U.S. patent 5,427,991. As taught
for
metallocene catalysts in these documents, the catalyst complexes of this
invention may be
either adsorbed or absorbed, on the polymeric supports, particularly if made
up of porous
particles, or may be chemically bound through functional groups covalently
bound to or in
the polymer chains.
Suitable solid particle supports are typically comprised of polymeric or
refractory
oxide materials, each being preferably porous, such as for example, talc,
inorganic oxides,
inorganic chlorides, for example magnesium chloride, and resinous support
materials such as
polystyrene polyolefin or polymeric compounds or any other organic support
material and
the like that has an average particle size preferably greater than 10 um.
The preferred support materials are inorganic oxide materials, which include
those
from the Periodic Table of Elements of Groups 2, 3, 4, 5, 13 or 14 metal or
metalloid oxides.
In a preferred embodiment, the catalyst support materials include silica,
alumina, silica
alumina, and mixtures thereof. Other inorganic oxides that may be employed
either alone or
in combination with the silica, alumina or silica-alumina are magnesia,
titania, zirconia, and
the like.
It is preferred that the carrier of the catalyst of this invention has a
surface area in the
range of from about 10 to about 700 m2/g, pore volume in the range of from
about 0.1 to
about 4.0 cc/g and average particle size in the range of from about 10 to
about 500 pm.
More preferably, the surface area is in the range of from about SO to about
500 m2/g, pore
volume of from about 0.5 to about 3.5 cc/g and average particle size of from
about 20 to
about 200 pm. Most preferably the surface area range is from about 100 to
about 400 m2/g,
pore volume from about 0.8 to about 3.0 cc/g and average particle size is from
about 30 to
about 100 pm. The pore size of the carrier of the invention typically has pore
size in the
range of from 10 to 1000, preferably 50 to about SOOA, and most preferably 75
to about
350th.
The catalysts of this invention are generally deposited on the support at a
loading
level of 100 to 10 micromoles of transition metal compound to gram of solid
support; more
preferably from 80 to 20 micromoles of transition metal compound to gram of
solid support;
and most preferably from 60 to 40 micromoles of transition metal comp6und to
gram of solid
support. While the catalyst can be deposited on the support at any level up to
the pore
volume of the support, loading levels of less than 100 micromoles of
transition metal
CA 02257796 2004-09-29
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compound to gram of solid support are preferred, with less than 80 micromoles
of transition
metal compound to gam of solid support being even more preferred, and less
than b0
micromoles of transition metal compound to gram of solid support being must
preferred.
Gas phase processes use supported catalysts and are conducted under gas phase
conditions suitable for ethylene homopolymtrs or copolymers prepared by
coordination
polymerization. Dlustrative cxamplts may be found in U.S. patents 4,543,399,
4,588,790,
5,028.670. 5.352,749, 5.382.638. 5.405,922. 5.422,999, 5,436,304, 5,453,471,
and
5,463,999, and I~tivnal applications WO 94/28032, WO 95/07942 and WO 96/00245.
Typically the processes are conducted at temperatures of from about -
100°C to 150°C, preferably
from about 40°C to 120°C at pressures up to about 7000 kPa
typically from about 690 kPa to
2415 kPa. Continuous processes using fluidized beds and recycle streams as the
fluidizing
medium are preferred.
Slurry polymerization processes, including loop slurry, in wlv,ch tlae
irnrnobilized
catalyst systems of this invention may be used are typically described as
those in which the
polymerization medium can be either a liquid monomer, like propylene, or a
hydroca~rbott
solvent or diIuent, advantageously aliphatic paraffin such as propane,
isobutane, hexane,
heptane, cyclohexane, etc. or an aromatic one such as toluene. The
polymerization
temperatures may be those considered low, e.g., less than 50 °C,
preferably 0 - 30 °C, or
may be itt a higher range, such as up to about 150 'C, pretbrably I'Irom 50
°C up to about 80
°C> or at any ranges between the end points indicated. Pressures can
vary f~otn about 100 to
'about 700 psia (0.76.~t.8 MPs). Additional description is given ira U.S.
patents 5,274,056
and 4,182,810 and WO 94/21962. Preferably for both gas phase and slurry
process the
polymerization reaction temperatures will be maintained at a temperature at
least 10°C below the
melting point of the polymer being produced.
In the process manner discussed above with the invention catalysts described
in this
application, unsaturated monomers, that is olefinically or ethylenically
unsaturated
monomers, may be polymerized so as to form polymer products having molecular
weights
(welgtat-average or ~,.,) from about 500 to about 3x106. lost typically, the
polymer
products will have an 1~", of tom about 1000 to shoos 1.Ox 106 and will have
narrow
mole~a~lar weight distribution $om about 1.9 _ d.0_ Suitable unsaturated
monomers will
include ethylene, C,-C~ ac-olefins, C,~-G,o cyclic ole$ns, C,,-C~ non-
conjugated diolefins,
C,-Cm gem-substituted oleSns, or C~-C,~ a-olefin macromers, and C,-Cm aromatic
substituted olefinx_ Preferably the polymer products will be any of
polyethylene
CA 02257796 2004-09-29
- 13 -
homopolymers, ethylene copolymers, particularly polyethylene plastomers arid
elastomers.
And, in view of the known tolerance of the catalysts to polar monomers,
ethyleNcally
unsaturated polar monomers witl additionally be polymecizable or
cvpolymerizable, The
preferred polar monomers include C,-Cso olefins containing functional
groupings such as
S esters, carboxylates, nitrites, amines, amides, alcohols, halides carboxylic
acids and the like.
More prelbrably vinyl esters, halides and nitrites. ,AJso. the txxasked
monomers o:f U.S. Paterrc
4,987,200 are also suitable.
Preferred polymer products enabled through the practice of this imrention can
have
1 O unexpected higher melting points than polytners from similar unsupported
catalyst complexes
when used in solution polyaterizatlon processes. Thus polymers with melting
points of ac
least 125°C will be possible despite the branch-producing tendencies of
these late transition
metal complexes.
15 Another important character'tstlc of the polymer of the invention is its
composiuon
distribution (CD). A measure of composition distribution is the "Composition
Distribution
Breadth Index" ("CDBI"). CDBI is defined as the weight percent of the
copolymer
molecules having a comonomer contertt within 50% (that is, 25% on each side)
of the
median total molar comonorner content. The CDBi of a copolymer is readily
determined
20 utilizing well known techniques ~or isolating individual Fractions o~ a
sample o~ the
copolymer. One such technique is Temperature Rising Elution Fraction (TREE),
as
described in Wild, et al., J. Po . Sci., Poly. Phys. F..d., vol. 20, p. dal
(1982) and U.S. Patent
No, 5,008,204.
25 To determine CDBI, a solubility distribution curve is first generated for
the
copolymer. This may be accomplished using data acquired from the T'REF
technique
described above. This solubility distribution cure is a plot of the weight
fraction of the
copolymer that is sofubilized as a function of temperature, This is converted
to a weight
fraction versus composition distribution curve. For the purpose of simplifying
the correlation
30 of composition with elution temperature the weight fractions are assumed to
have a Mn z
I 5,000, where Mn is the number average molecular weight fraction. Low weight
fractions
generally represent a trivial portion of the polymer of the present invention.
The remainder
of this description and the appended claims maintain this convention of
assuming all weight
fractions have a Mn Z 15,000 in the CDBI measuremem.
From the weight fraction versus composition distribution curve the CDBI is
determined by establishing what weight percent of the sample has a comonomer
content
within 25% of each side of the median comonvmer content. Further details of
determining
CA 02257796 2004-09-29
- 14 -
the CDBI of a copolymer are known to those skilled in the art. See, fvr
example, PCT
patent Application WO 93/03093, published Febnrary 18, 1993.
The polymers of the present invention in one embodiment have CDBI's generally
in
the range of greater than 50'/o to 99%, prefbrably in the range of 50% to 85%,
and more
prel'ierably 55% to 80%, even more prefhrably greater than 60%, still even
more preferably
greater than 65%. Obviously, higher or lower CDB)('s may be obtained using
other catalyst
systenn~s with changes in the operating conditions of the process employed.
1 o For the following e~x,amples, all molecular weigh=s are wdglat average
molecular
weight unless otheryvisc noted. Molecular weights (weight a~reragc molecular
weight (Mw)
and number average molecular woight (M~ were measured by Gel Permeation
Chromatography, unless otherwise noted, using a V,Iaters 150 Gel Permeation
Cbacom~atograph equipped with a di~rential refractive index detector and
calibrated using
15' polystyrene standards. Samples were run in either TGIF (45°C) or In
1,z,4-trichlorobenzene
(145°C) depending upon the sample's solubility using three Shodex GPC
AT-80 M/S
columns in series. This general technique is discussed in "Liquid
Chromatography of
Polymers and Related Materials )~', J. Cazes Ed., Marcel Decker, 1981, page
207. No corrections for
column spreading were employed; however, data on generally accepted standards,
e.g.
20 National Bureau of Standards Polyethylene 1475, demonstrated a precision
with 0.1 units for
Mw/Mn wwch was calculated from elution times. The numerical analyses were
performed
using Expert Ease* software available from Waters Corporation.
25 EXAMPLES
l~nration of Suy orted Catalysts
Transition metal precursors used to illustrate the imrention were those
described in
Table I.
*TM
CA 02257796 2004-09-29
~ 15 -
Table L ?ransition Metsl ?reeursor Structures.
,X N~ ,Br
Structure Ni Ni
~X N~ ~Br
~r w n (CsMcs~z- (CsFIs~-
' ZrCia ZrCh
Designation TM-1,'X = Cl
'li'M-2, X = Br TM-4 T'M.5 TM-6
TM-3, X = Me
Example 1
Genera! Supporting Method
M alumiaoxane, such as methyialmoxane or modi$ed alurnc~xane. yr other
suitable
activator such as Al(CH3)3, Al(CHZCH3)2C1, H(C6F'S)~, LC6HSNMe2H]+[H(C6F5)4]-.
[(C6H5)3C]+[B(C6F5)a]". CFi]+(BFa]", fH]+[PF6]~> [Ag]+(BF4]', [A,g]+[PF6]". or
[Ag]'*[B(C6F5)4]- is combined with one or more transition metal complexes in
an
appropriate solvent to form a precursor solution. A suitable support,
preferably porous, is
charged to a vessel and the precursor solution is added with stirring. The
mixture may be
mixed by hand with a spatula, by s rotating stirrer with wire loops such ~ a
Kitchen Aid
dough mixer, by metal blades rotating at high speed such as in a Wehring
blender, by a
helical ribbon bladed mixer, by ahalang, tumbling, fluidized bed mi7dng, by
paddle or
propeller blades on a rotating stir shaft, or other appropriate means. The
total amvurrt of
solvent used to form the precursor suspension or solution may be lass than the
pore ~olurne
of the support as in impregnation to incipient wetness, or greater than the
pore volume of the
support such that a slurry is formed, or an amount is between such that a
solution-finely
divided support mixture is neither free flowing nor a slurry. Solution may be
added to
support or vice versa as appropriate to the mixing method. If desired the
liquids may be
removed by purging with an inert gas or under vacuum.
*TM
CA 02257796 2004-09-29
- 16 -
Support Mct6od
An aluminoxane or suitable activator was combined with the transition metal
complexes in toluene to form a precursor solution, The solution was charged to
a ve3sel and
the porous support added all at once and the mixture stirred by hand with a
spatula. The
total volume of the precursor solution was greater than the pore volume of the
support, but
not enough to reach the point of gelation or form a slurry, about 100%- 200%
pore volume.
'the solvent was removed in vacuo (press. < 200 mTorr) and ambient temperature
overnight,
about 12 - 16 hr.
The aluminoxane used was 30 wt'r6 mathyl aluminoxane supplied in toluene by
Albemarle. The silica was M5948 ( 1.6 cc/g P. V. (P. V. = Pore Volume).
Davison Chemical
Co) previously heated at 600°C under Nx for 3 hours, and the toluene
was air and moisture
free from Exxon Chemical.
Table Ix. Supported Catalyst Preparation Dats.
Es Me- TM TM TM MAO Tvl. Si02 TM P.V.
thod used (m8) (pmol) (g) (g) fig) ttmoVg solo."
support
S-1 1 TM-1 88 16S 3.9 1.8 3.0 55 1.3
S-2 1 TM2 106 170 3.9 1.8 3.0 57 1.3
S-3 Z TM-4 118 164 3.9 1.8 3 .0 S S 1.3
5-4 1 TM-4 1200 1668 38.1 38.9 30.0 56 1.7
S-5 1 TM-4 1204 16'T4 38.1 38.9 30.0 56 1.7
'P.V, solo. = Ratio of total precursor solution volume to support Pore Volume
(~8)~
Polymerization Reaction E=ampler
Polymerization Method i: Cootiauous Fluidized Bed Gas Phase Polymerizations
Under conditions described in WO 96/00245, a continuous cycle fluidized bed
gas phase
polymerization reactor was used for the ethylene polymerization studies
summarized in Tables III and IV.
The approximate dimensions of the reactor section above the distributor plate
and below the
disengaging head were 4 in. ( 10.2 cm.) in diameter and 24 in. ( 61 cm.) in
length. Total
operating pressure was 314.7 psia ( 2170 kPa) (gas compositional makeup
described in
Table III with the balance being N2) and polymer samples were collected after
several bed
* TM
CA 02257796 1998-12-07
WO 97/48736 - 17 - PCT/US97/104I8
turnovers. Detailed process descriptions are given in Table III and product
characterization
data in Table IV.
Table III. Polymerization Method 1 Process Conditions.
Example CatalystC2 mol%H2/C21 C Bed g PE/g
' Turnovers2 Cat
P1-1 S-4 60.4 0.1 39.2 2.7 228
P1-2 " 62.1 1.4 41.6 5.0 344
P1-3 S-5 69.4 14.6 43.5 2.8 343
Pl-4 " 70.2 14.8 54.5 4.1 367
Pl-5 " 70.4 19.8 63.0 3.1 296
'mol ppm H2/mo1%C
z Number of times the starting polymer bed displaced.
3 Productivity based upon material balance of catalyst fed into reactor and
polymer
removed.
Table IV. Polymerization Method 1 Product Data.
Ex. CatalystDensityMelt MP Branch Mw 4 MWD
Index C2 1 H NMR ( 10-3)
~ 3
P1-1 S-4 0.9107 no flow 117.2 18.4 564 2.77
P1-2 " 0.9105 no flow nm 20.4 665 2.70
Pl-3 S-5 0.9103 no flow 118.86 19.6 590 2.80
P1-4 " 0.9061 no flow 115.9 26.5 525 2.86
Pl-5 " 0.9013 no flow 91.0, 33.6 435 2.68
114.4
1No significant flow under standard ASTM melt indexes conditions.
2Peak melting temperatures by DSC.
3Methyl groups per 1000 carbons
4Samples showed some mass loss during GPC analysis.
Polymerization Method 2: Semi Batch Slurry Polymerizations
Conditions of the polymerization examples are given in Table V.
Polymerizations
were performed in 400 mL of dry hexane in a nitrogen purged 1 L Zipperclave
reactor
(Autoclave Engineers) equipped with an external temperature control jacket. In
a glove box
CA 02257796 2004-09-29
- Za -
a charge of the supported catalyst, usually 50 to 200 mg, was loaded into a
short length of
SS tubing between two ball valves and backed by a small bomb containing 20 mL
dry
hexane. This device was attached to the reactor under an N2 purge. Unless
noted
otherwise, cocatalyst (0.200 mL 25 wt% triethylaluminum in heptane) was
injected into the
reactor as well as comonomer, if noted, and the mixture heated tv operating
temperature
with stirring. Stirring was stopped and the catalyst flushed into the reactor
by the hexane
backed with ethylene or nitrogen pressure. Stirring was immediately restarted
while the
reactor reached its regulated operating pressure corrected for solvent vapor
pressure.
A$er sufficient reaction occurred the reactor was vented and the contents
slowly
poured into a beaker with 1 L of stirred acetone under air and filtered.
Alternately the
solvent could be removed under vacuum or by an impinging nitrogen stream. The
separated
polymer samples were then dried overnight in a vacuum drying oven at about 50
°C.
Comparative Polymcrixation Method 3: Semi Bstch Solution/Suspenslon
Poiymerizationa
Conditions of the polymerization exampies are given in Table V.
Polymerizations
were pcrfotmed as in Mdhod 2 with the following exceptions. Nv
triethylalununum was
used. Instead 10 wt% methylaluminoxane in toluene from Witco was introduced
into the
resctor as both scavenger and activator. The transition metal compounds were
introduced
into the reactor as solutions in toluene.
Comparative Polymerization Method 4: Semi Bstch Polymerization in Tolune
This is a method of the comparative exampits (C1-C3) disclosed in Brookhart,
et al,
supra.
Comparati a Polymerization Method 5: Semi Batch Solucion/Supension
Polymerization
Conditions of the polymerization examples are gloss in Table v_
Polymerixations were
performed as in Method 3 with the following exceptiow toluene was used as the
polymerization
solvent.
* TM
CA 02257796 1998-12-07
WO 97/48736 PCT/US97/10418
_ i9 _
0 0 0 0 0 0 0 0 0 ~ ~ 0 0 0 0
o ~ r o o a~ ~ ,-~.-io 0 0 0 0 0 0 0
O J.-~ l0 O O tI7N ~T 1l~Oo OD V'l0 O .-1N Cor-i (d I
'
rl a~ l0 tnO OD O d'~ lD r rl r ~., ?i
.~1 W M M M M ~ N N 00Ol 00"~;
rt1 r-1
cd W O ~
U .i-~ O
P4 ~ Q,
~ ~ ~
N .-1CO to r-ir-1r-iC' ~' N cr l0 v~In M O .-I
a
''I N N ri ~ tnC' ~ 07 O N l0 W (7C' V~S-i >'I
a~ is ,-a .~ ~"~~ II O C~
''I .~ M
W ccf
W
O h h h l0 ~ l0 l0e-iO ~ ~ O O O O
M M M ~- W .-1r-Ilf~N tn'~'~T C?'d' C
~ -i
I ~ O ODCO r-1ri.--1v-I'-1N '-1~' ~ ~ ~ ~ ~
O
,
.-i,--i,-i .-I~ ~ ~ td
N ~ ~ ~ ~ N ~C
(~,,
.IJ
N
O U
.C ~ E' s~ 'O O O
.1~ O ~ U
G1 N N N ( I N N N N N N N N
~, ~ ,~ M M M M M M M M M M M -~ O ri .-I
~ ~ ~ ~ ~ u7u7 ~t~W ~ u7w ~ ~ td
+~ ~ .-i.-a~ 1 I .-a'--i~ ,--a.--a~ '-i~
U ~
~ cd
ro ~ ~ ~ a~ s~
A
M M M M M r r M tn M 00 O O 01 01
ao 0oao rn co~ ~ .-~o~ ,--mr O O o~ a~II
~ N ~'
O O O r r M M O ~O O M .-1r--1 ~-r .
.,..I
E-~ .~ N
f0
Id U S-~
N rtS O ~ ~d
rI ~ S-1
f.l 5C II U !~
+.~
.1-.~ O O O O ~ O
-
rd ~ I I I O O O O 1 I I I I I I I
U ~ N N .-1,-i O p ~ b
z .~,
o ~ o v~ o
W O O O O O O O O O O O O O O O O U ~ fd
M M M Ol M M OlM M M M M M M M "a rtl .C~
h
"Cj t0
O ~ +~
r~ b O 'L7 E-~
~-1
f.-1 :~ "O
~d
U O O ~n o 0 0 0 o 0 0 0 0 0 0 0
0 o N l0 l0M M lp l0 lpl0 lD lfll0 l0~ O ~ U
V~ O .C (n r-I
U
~
r oor O O O o o O o O O o O O v
II ~-I
w ~r m ~r u W O u W u1 u Wr7O O O O p
.n r'>
II N ,-.mn,-ir r o r r r r r co 0oao 00.,~ II ~ b
~n O
U !~ M +~ U U O ~
rd -r-I ~1.
a
N
'C1 ~
-I v m ~ c
n
0
W ~ ~ ~r~ N N N N M M M cr1tn tnu1 Ir7~ ~ ~ >~
O N td
U
~..I O
rt w N cn ~n
s~
a1 y. ~T ~!c c~ cr M ~ N N M M
~
, i I 1 N clN N I I I I 1 I I I (I II W f~
,
V ~ ~ ~ i W v i ~ ~ ~ ~ ~ ~ ~ ~
c ~ c x a N +-~
~
U U ~ O
N ~ D
r-1 x .-iN c1 ~Tr-IN c'r1c~ O -~I ~,
.A W ~ N M I I I I I I I I c W l0 t~~ .t~ .>~
f1
(p I I 1 N N N N M M M M I I I 1 U ~
H U U U W W W W w f~ w LL U U U U ~ it v
CA 02257796 1998-12-07
WO 97/48736 PCT/US97/10418
- Zp -
..
N N
O O O O O O O O O ~ ~ O O O O
O
N
N M ~ C C G ~ C C G
N
Id
A H
O ~ '~~~ ~ dh.'E
C C" h C r-r~ C' ppC Ov
N
.~
id
O O O r W O oo ~ O O O O
O
N r O 00 O~h ~O O N 00 M
N h o0 00 00~ Ov o000 h h
O ~ E ~ ~ o
(~ C C C
0 x ~
_
.) 00 O O ~'O M M M M
II
d'M N o0Ov N M N N N N N N N N
O H
N N N N --~
'CS ~? O O O ~n~O O 00M V~h h M vD
O O O ~ N h o0 O ~n ooN O ~n~ h ~DO
~1'M O ~OM ~ ~ N M M M M
3
o ~ o c
'~h~ ~' N N N N M M M M ~ ~ ~ ~ -fl O
U U
V
.
W N O O
at i i ~ M ~tM wT N N M M
N V~ N N i ~ i ~ ~ ~ ~ ~ ~ Ch
U ~ E"'~H ~ ~ pn CY
H C%~C/~V~ V1H E"'iE""F' E.~.'~'
O ~' ~ V C
N M ~ N M ~ ~ N M ~ ~ ~ ~D h ~ I~
U iC ~
U U a,w w H a, a.aM..~aM.,U U U U U ~ N~ ~,~
w
CA 02257796 1998-12-07
WO 97/48736 - 21 - PCT/US97/10418
Table VII. Predicted vs. Observed Branching in Continuous Flow Fluidized Bed
Gas
Phase Polymerization.
Ex. Cat C psid Me/103C MP den-
(kPa} C sity
C-1 TM-4 0 14.7 24 112 -
(101)
C-2 TM-4 0 58.8 5 122 - -0.431
(405) branch/psi
vs.
C-1
C-3 TM-4 25 14.7 71 39 +1.88
( 1 O branch/C
1 ) vs.
C-1
calcu- TM-4 63 222 53 66 - Extrapolated
lated ( 1531 from C-2
)
Com .~ - - - 83 30 -
Pl-5 S-S 63 222 33.6 91 .901
(1531)
Commercial ethylene copolymer, VistalonTM EP rubber 203, with 18.3 mol.%
ethylene
and 81.7 mol.% propylene (Exxon Chemical Co.)
From examination of Table VII and exampies C-1 to C-3 reported by Brookhart,
et
al, supra, we observed that branching of the polymer C-1 decreased from 24
branches/1000
carbon atoms at 14.7 psia ethylene to 5 branches/1000 carbon atoms in C-2 at
58.8 psia
ethylene. From this, one skilled in the art is led to believe that branching
would decrease by
0.431 branches per one psid increase in pressure (0.063 branches/kPa).
Similarly comparing
examples C-1 and C-3 one skilled in the art is led to believe that branching
would increase by
1.88 per °C of temperature increase. Frorn these observations it would
appear that upon
increasing both temperature and pressure from those of example C-2 (58.8 psi
(405kPa), 0
°C) to those of the typical continuous cycle fluidized bed gas phase
polymerization process in
example P 1-S (222 psia ( 1531 kPa), 63 °C) the branching would
increase from 5
branches/1000 carbon atoms to about 53 branches/1000 carbon atoms. By
comparing
branch counts vs. MP for the three examples C-1, C-2 and C-3 as well as a
commercial
ethylene copolymer (VistalonTM EP Rubber 203) and the polymer-obtained from
the
supported catalyst of example P1-5, a linear relationship is derived such that
MP = -
1.275(#Me/100°C) + 134.038 with R= 0.991. Using this equation, one
would predict that a
CA 02257796 1998-12-07
WO 97/48736 - 2 2 - PCT/US97/10418
polymer having 53 branches/1000 carbon atoms would have a MP of 66°C.
This is very near
the typical operating temperature of commercially viable gas phase
polymerization processes
and would likely result in fusion of partially melted polymer particles formed
in the reactor
and consequent loss of fluidization. Surprisingly, however, under the
conditions examined in
S Tables III and IV, these difficulties were not observed. Instead, the
polymer produced had
34 branches 1000 carbon atoms and MP of 91°C rather than the calculated
53 branches/1000
carbon atoms and MP of 66°C. Additionally, the particle morphology
observed was
excellent and the production of fines was low.
Additionally, it was observed that the selection of a late transition metal
catalyst
system and its being immobilized on a solid particle support for slurry
polymerization in
accordance with the invention resulted in unexpected modifications in the
polymer
characteristics. The late transition metal catalyst system TM-4 exhibited a
significant drop in
MW from 185,000 to 76,000 when run unsupported (P3-2) and supported (P2-2)
while the
late transition metal catalyst system TM-2/TM-3 exhibited the essentially
insignificant drop
from 353,000 to 325,000 (P3-1 vs. P2-I) when run under similar conditions. It
is likely that
the conjugated groups on the bridge TM-4 are affected in some manner by being
supported
on the solid particle such that the MW is decreased. Thus, selection for
molecular weight
tailoring can be guided by this observation, lower molecular weights can be
achieved with
those late transition metal catalyst system compounds having the conjugated
groups on the
bridge (e.g., A-1 I through A-14 above) when a catalyst of this class is
supported and utilized
in slurry or gas phase processes. In support of the comparison of the
dibromide vs. dimethyl
starting complex, Brookhart, in JACS '95 p. 6414 Table entries 5 & 6, shows
equivalent
behavior for cationic methyl complexes and the dibromide complexes plus MAO.
This is
similarly supported by comparative examples C4-C7 of this application.
Supporting the catalysts in accordance with the invention also appears to
cause a
decrease in branching (branches/1000 carbon atoms). Thus the use of TM-4 in
example P3-2
exhibited 89.0 branches/1000 carbon atoms while the use of the same catalyst
supported in
example P2-2 exhibited 80.1 branches/I000 carbon atoms, a decrease of about
10%.
Similarly, the use of TM-3 in example P3-1 exhibited 88.6 branches/1000 carbon
atoms
while the use of the dibromide derivative TM-2 in example P2-1 exhibited 74.7
branches/1000 carbon atoms, a decrease of about 15%. Since branching is
directly related to
density and to melting point {MP) the differences will provide significant
advantages for
particle form processes such as gas phase and slurry polymerization processes.
The use of the supported catalyst systems of the invention also allow for
increases in
both MW and activity as compared to that to be expected from the teachings in
the prior art
CA 02257796 2004-09-29
~3
with respect to use in solution polymerization of the late transition metal
catalyst systems.in
unsupported form. Example P2-3 can be compared to P2-4 for exempiiflcation of
the
increased MW from increased pressure when the catalysts are supported, the MW
was
1.086x106 at 300 pain (2068 kPa) and 6.08x10s at X5.0 psia (517 kPa). The
examples of
Brookhart, et al, (Table V, C-1 vs. C-Z) illustrate that one ckilled in the
art would expect
little change in MW from increasing pressure, the Mw was 1.6x10 at 14.7 pcia
(101 kPa)
and 1,4x106 at 58.8 pain (405 kPa). Additionally, the polymer product yields
of Brookhart,
et ol, supra, were essentially unchanged by the exhibited pressure change (2.1
g and 2.2 g,
both after 30 min.). Tho supported catalyst of examples PZ-3 and PZ-4 showed
chat at
higher pressure, only 20% less polymer was produced despite being run oNy one
third of the
time.
